This invention relates to a method of and apparatus for performing thermal-transfer recording and, more particularly, to a thermal-transfer recording method capable of stably printing an image on any desired recording medium and to an apparatus used for this method.
Recently, as information systems have improved, there have been increased demands for the provision of various types of output as hard copies. A recording apparatus used to realize such hard copy outputs needs to have improved operability, maintainability, and reliability and also be smaller and quieter. To satisfy these requirements, heat-sensitive recording apparatuses are widely used in facsimile systems, copies, and similar devices. However, a thermal-transfer recording apparatus has a disadvantage in that it necessitates heat-sensitive recording paper which contains coloring substances within the paper itself, and therefore it is not capable of printing on other types of paper. In addition, it is not possible to realize any continuous tone color on heatsensitive recording paper and, hence, obtain the type of color image which is formed by superposing single-color images having continuous tone color.
A type of thermal-transfer recording apparatus which makes use of a sublimable ink tape formed by applying sublimable dyes to the surface of a base film has been known as an image recording system for obtaining single-color image prints and color image prints displaying continuous tone color. An example of this system is disclosed in Japanese Patent Laid-Open No. 169370/1982. In this thermal-transfer recording apparatus, a sublimable ink tape and recording paper having a support layer and an ink absorbing layer formed on the support layer are used; and the sublimable ink tape is heated by a thermal head so as to liberate the sublimable dyes from the base film and fix them to the absorbing layer of the recording paper, thereby obtaining an image print. This system enables single-color image prints and color image prints displaying continuous tone color, but it necessitates special recording paper having a layer into which sublimable inks are absorbed and therefore it cannot form image prints on any other desired recording medium such as letter paper, postcards, high-quality paper, and cloth. This system is also defective in that an image print formed in the above-described manner changes with the passage of time as the sublimable dyes fixed to the recording paper sublime therefrom.
A method of preventing this kind of change in an image print with the passage of time is disclosed in Japanese Patent Laid-Open No. 147390/1983. According to this method, a laminated film is heat-bonded to the surface of the recording paper after recording so as to prevent any re-sublimation of dyes from the absorbing layer of the recording paper. This method can prevent th image print from changing with the passage of time, but it is still incapable of forming image prints on any desired recording mediums.